Expanding rotary underreamer



March 17, 1931- J. B. TRIPLETT EXPANDING ROTARY UNDERREAMER OriginalFiled April 16, 1923 2 Sheets-sheet 1 JYI L YTOZ JQMES B 7k/PLET 7,

ATTORNEYS March 17, 1931. J, TR|PLETT 1,796,546

EXPANDING ROTARY UNDERREAMER Original Filed April 16, 1923 V 2Sheets-Sheet 2 M/Wrok Jan x55 5. 7720 4 5 T r,

FZWTOKHEi g:

Patented Mar. 17, 1931 um'ren sr'rss PATENT OFFICE JAMES B. TRIPLETT, OFHITTIER, CALIFORNIA; WILLIAM H. CAMPBELL, OF LOS ANGELES, CALIFORNIA,AND WILLIAM H. MAXWELL, OF BEVERLY HILLS, CALI- FORNIA, EXECUTORS 0FSAID JAMES. B. TRIPLETT, DECEASED, ASSIGNORS TO JOHN GRANT, OF LOSANGELES,

CALIFORNIA EXPANDING RDTARY UNDERREAMER Application filed April 16,1923, Serial No. 832,295. Renewed December 12, 1927.

This invention relates to rotary well drilling equipment and relatesparticularly to expanding underreamers employed in rotary well drillingequipment.

I In drilling oil wells, considerable, difficulty is encountered inmaintaining the full diameter of the bore, because of the wearing oit ofthe corners and the sides of the drill bit, so that the bit will not cuta hole to the intended full diameter. It is necessary that the fulldiameter of the hole he maintained in order that the well casing mayenter freely into the well as it is installed. It is necessary, underthis condition, to'employ an underreamer to ream the hole to the fulldiameter to permit the casing to advance. l

The underreamer generally employed for this purpose is of the expandingblade type,

which is lowered through the casing to the point at which it is tooperate and the blades thereof expanded. In order to employ anunderreamer of this type, it is necessary to pull the drill and attachthis underreamer to the lower end of. the drill tubing and then to lowerthe underreamer into the well. Before drilling can then be resumed, theunderreamer must be removed from the well and replaced by the bit. Itwill be readily seen that much time is consumed by the changing oftools, and that when drilling through hard rock, where the drill wearsvery quickly, most of the time is spent in removing and replacing tools.

It is an object ofthe invention to provide 5 an underreamer which isscrewed to the Referring to the drawings, which are for illustrativepurposes only:

' Fig. 1 is a diagrammatic view illustrating the utility of myinvention.

Fig. 2 is a vertical section of my invention showing the reamingelements in retracted As shown in Fig. 1, a well 11 is being drilled bya bit 12 which is attached below an underreamer 14. embodying thefeatures of my invention to a drill tubing 15. The drill tubing isrotated by a rotary table 16 located at the surface, which causes thedrill to sink the hole. In time, the drill will so wear that it will notcut the hole to the full diameter required, and it would be impossibleto advance the well casing 17 downwardly if it were not for theunderreamer 14:. The underreamer 14 has reaming elements which are inreaming position during the time thebit12 is working, and as the drillwears and begins to cut the hole slightly undersize, the reamer elementswill maintain the hole to a suflicient size to allow the casing 17 to beadvanced. 'VVhen it is necessary to pull the drill tubing to replace thedrill after it has Worn considerably so that it will not cutefiiciently, the

underreamer is so constructed that the reamer elements will be.retracted into a position within the body of the underreamer and will 7pass through the well casing without interference.

In the remalnlng figures I'show an underreamer of my invention, indetail. The underreamer l lconsists of a main body 20 comprising anupper section 21 and a lower section 22. The upper section has athreaded pin 23 at its upper end for attachment to the drill pipes, andhas a reduced rectangular portion 24 at its lower end which has atapered dovetail slide 25 symmetrically disposed at its lower end, andwhich portion extends into the slides in a corresponding opening 26formed in the lower member 22. The members 21 and 22 are in limitedsliding relationship, and, as shown in Fig. 4, the upper end of themember 22 is provided with slide limiting studs 28 which extend throughholes 29 in the member 21 into recesses 30 provided in the member 21.When the members 21 and 22 are together, as shown in this figure and inFig. 3, the top face 31 of the member 22 and the face 32 of the member21 are together, and when the members 21 and 22 are apart, as shown inFig. 2, the nuts 34 on the upper end of the studs 28 engage the face 36of the recess 30. The lower member has a threaded box 37 by which a bitmay be attached thereto and has a slot 38 therein in which the remainingelements 40 are located. These reaming elements 40 are of circular crosssection and the surface thereof is prepared in tooth formation to forman eiiicient reaming engagement with the wall of the hole, and thesereaming elements 40 are rotatably mounted between blocks 41 and pivotedmembers 42. The blocks 41 are slidably engaged with the dovetailedslides 25, and the members 42 are pivotally mounted on pins 43, whichmembers have the lower faces 44 thereof formed concentric with the pins43 and rest on the bottom of the slot 38, so that any stress placed onthe reaming elements 40 will be supported by the faces of the slots andnot the pins 43, which are merely retainers.

It will readily be seen that by providing reaming elements of circularcross-section and by rotatably mounting them, that a very extensivecutting surface may be provided.

As hereinbefore mentioned, the reamer elements are adapted to assume twopositionsthe reaming or expanded position and the non-reaming orretracted position, the manner in which these two positions arecontrolled will now be described:

When the drill bit is in operation most of the weight of the drilltubing thereabove is placed on the bit, the weight sliding the members21 and 22 together, as shown in Fig. 3. In this figure, the wide portionof the dovetailed slide 25 is engaging the blocks, and the reamingelements 40- are in expanded or reaming position and remain in thisposition during the drilling operation. When the drilling is stopped,possibly to replace the drill, and the drill tubing is moved upward, theupward movement of the tubing first moves the upper member 21, the lowermember 22 and the drill remaining stationary until the nuts 34 on themembers 28 are engaged' by lower face 36 of the recess 30; then thelower portion 22, and the drill are carried upwardly therewith. As shownin Fig. 2, the relational movement of the members 21 and 22 moves theslide 25 upwardly also and brings the narrow portion of the slide intoengagement with the blocks 41 causing them to move inwardly and to swingthe reaming elements inwardly into non-reaming position. lVhen thereaming elements are in this position they are resting within the bodyof the underreamer and will in no way interfere with the lowering orraising of the underreamer through the casing. To prevent any drillingsor mud from lodging between the faces 31 and 32 of the members 21 and22, I provide a protective sleeve which is mounted on the upper member21 and extends around the upper portion of the lower member 22. Thesleeve 50 also encloses the recesses 30, into which the slide limitingstuds extend.

Lubricating mud may be conducted to the bit through the passage 53 whichextends through the upper member 21 and the pipe 54 which is screwed tothe lower end of the slide 25, the lower end of which passes through thepacking gland 55 to compensate for the sliding relationship of themembers 21 and 22.

From the foregoing, it will be seen that a great deal of time is savedby eliminating the necessity of removing the bit to ream the hole to asize suflicient to allow the well casing to be advanced.

t will also be recognized that with the construction I employ a positiveoperation of the reamer elements between expanded and retractedpositions is accomplished.

This application is companion to a later one filed May 10th, 1926, Ser.No. 107,999 and similar in subject matter. The common subject matter ofthe two is herein claimed; claims of the later application are limitedto to its differences over this one.

I claim as my invention:

1. A rotary well underreamer of the character described including twobody sections movable relative to each other longitudinally of theunderreamer, one of the body sections having a. channel, a projection onthe other body section extending into the channel, expansibly disposedand separately rotatable reamer elements each pivotally connected at itslower end to one of the body sections and slidably connected at itsupper end to the other body section, and means whereby said reamerelements are expanded when said body sections are relatively slid in onedirection and are retracted when said body sevtions are relatively slidin the opposite direc tion, said means including a tapered dovetailslide.

2. A rotary well underreamer including a body composed of two relativelylongitudinally movable sections adapted to be secured one to a drillstring and the other to carry a rotary bit, expansible and separatelyrotatable reamer members supported upon said body, said reamer elementseach having one end pivotally connected and the other end shiftablyconnected to said body for radial movement, and means whereby saidreamer elements are expanded when said body sections are relatively slidin onedirection and are retracted when said body sections are relativelyslid in the opposite direction, said means comprising symmetricallydisposed tapered slides for expanding said reamer members into cuttingposition when the weight of the above drill string is placed upon thebody.

3. In an underreamer, the combination of: a body adapted toincorporation in a drill string; expansible reamer members support-- edupon said body, consisting of abrading rollers of tapered form pivotallysecured at their smaller ends, with their larger ends swingable betweenretracted and expanded position; and means for expanding said reamermembers into cutting position when the weight of above drill pipe isplaced upon said body.

4:. In a rotary underreamer oi the character described, the combinationof: a pair of relatively slidable members comprising an upper memberprovided with a pin and a lower member adapted to carry a terminal bit;a projection extending from one of said members into the other of saidmembers for transferring torque between said members; separablyrotatable reamer elements having their lower ends pivotally connected toone of said members and their upper ends slidably connected to the othermember; and means on said upper member for expanding said reamerelements when said members are moved together.

5. In a rotary underreamer of the character described, the combinationof: a pair of relatively slidable members comprising an upper member anda lower member; a projection extending from one of said members into theother of said members for transferring torque between said members;separably rotatable reamer elements pivoted at their lower ends to oneof said members and slidably connected at their upper ends to the othermember; and means on the other of said members for moving the upper endsof said reamer elements outwardly into expanded position when saidmembers are moved together. I

6. In an underreamer, the combination of a pair of relatively slidablemembers comprising an upper member and a lower memher; a projectionextending from one of said members into the other of said members fortransferring torque between said members; roller reamer elementspivotally mounted at their lower ends to one of said memupper ends ofsaid reamer elements; and a wedge member for forcing said blocksoutwardly into expanded position when said relatively slidable membersare moved together.

7. In an underreamer, the combination of, a body comprising tworelatively moving parts sliding longitudinally of each other, one ofsaid parts having a wedge surface, a block slidably engaging the wedgeand adapted to be moved laterally by relative longitudinal movement ofthe wedge, a cutter carrier pivotally mounted at one end on the otherbody part and connected at its other end loosely with the block to allowsliding of the block and swinging of the carrier about its pivot, and acutter mounted on the carmen 8. In an underreamer, the combination of, abody comprising two relatively longitudinally movable parts, one of saidparts being tubular and having slotted walls, and the other entering thetubular part and slidable longitudinally therein; a longitudinallyextending cutter carrier pivoted at one end to the tubular body part andlying in the body slot, an expanding wedge on the other body part, ablock lying in the body slot and slidably engaging the wedge to be movedin and out through the slot by virtue of relative longitudinal movementbetween the two body parts, the other end of the cutter carrier beingconnected to the block in a manner allowing the block to slide and thecarrier to tilt about its pivot, and a cutter mounted on the carrier.

9. In an underreamer, the combination of, a lower tubular body parthaving a slotted wall, an upper body part slidable vertically in thetubular part and having at its lower end a wedge, a block lying in oneend of the body slot and slidably engaging the wedge to be moved in andout through the slot by virtue of relative longitudinal movement of thetwo body parts, a cutter carrier lying in the body slot and pivoted atone end to the tubular body part at the other end of the slot, the otherend of the cutter carrier being loosely connected to the block allowingthe block to slide and the carrier to tilt about its pivot, and a cuttermounted on the carrier.

In testimony whereof, I have hereunto set my hand at Los Angeles, this3rd day of April,

JAMES B. TRIPLETT.

